Modelling and simulation of a robotic manipulator with six degrees of freedom attitude and orbit control for space applications

In space, docking involves joining of a capture spacecraft and a target spacecraft for various applications like repair, maintenance, replenishment of fuel and propellant, etc. In low impact docking process, an intermediate system is necessary to hold the target vehicle, which can be a robotic arm with an end effector like a finger gripper. The degree of freedom is a measure of the dexterity of the robotic arm and the design should be precise and accurate as it is involved in the process of capturing a free flying vehicle in space. Research is still in the nascent stage, therefore there is a requirement for high fidelity models to analyse forward kinematics, inverse kinematics, dynamics and closed loop control for a robotic manipulator taking zero gravity into consideration. The parts of the proposed six degrees of freedom manipulator are designed/simulated separately and assembled before demonstrating control aspects and visualization. The manipulator follows a joint space trajectory computed using inverse kinematics. The grab mechanism is achieved/visualized in a three-dimensional environment. These simulation results can be used directly to drive the hardware model in the future. The need for this research is relevant especially in the context of India's future space station development.